Schnell Melanie, Lützow Peter, Veldhoven Jacqueline van, Bethlem Hendrick L, Küpper Jochen, Friedrich Bretislav, Schleier-Smith Monika, Haak Henrik, Meijer Gerard
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany.
J Phys Chem A. 2007 Aug 9;111(31):7411-9. doi: 10.1021/jp070902n. Epub 2007 Jun 13.
A linear AC trap for polar molecules in high-field seeking states has been devised and implemented, and its characteristics have been investigated both experimentally and theoretically. The trap is loaded with slow 15ND3 molecules in their ground state (para-ammonia) from a Stark decelerator. The trap's geometry offers optimal access as well as improved loading. We present measurements of the dependence of the trap's performance on the switching frequency, which exhibit a characteristic structure due to nonlinear resonance effects. The molecules are found to oscillate in the trap under the influence of the trapping forces, which were analyzed using 3D numerical simulations. On the basis of expansion measurements, molecules with a velocity and a position spread of 2.1 m/s and 0.4 mm, respectively, are still accepted by the trap. This corresponds to a temperature of 2.0 mK. From numerical simulations, we find the phase-space volume that can be confined by the trap (the acceptance) to be 50 mm3 (m/s)3.
一种用于高场寻态极性分子的线性交流阱已被设计并实现，其特性已通过实验和理论进行了研究。该阱从斯塔克减速器中装载处于基态（仲氨）的慢速(^{15}ND_3)分子。阱的几何结构提供了最佳的进入方式以及改进的装载效果。我们展示了阱性能对开关频率的依赖性测量结果，由于非线性共振效应，这些结果呈现出一种特征结构。发现分子在捕获力的影响下在阱中振荡，并使用三维数值模拟对捕获力进行了分析。基于膨胀测量，速度和位置展宽分别为(2.1)米/秒和(0.4)毫米的分子仍能被阱捕获。这对应于(2.0)毫开尔文的温度。通过数值模拟，我们发现阱可以限制的相空间体积（接受度）为(50)立方毫米·（米/秒）³。
